• Journal of the Korean institute of surface engineering
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• v.39 no.3
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• pp.87-92
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• 2006

The characteristic of interface layer and the effect of bias voltage on the microstructure of c-BN films were studied in the microwave plasma hot filament C.V.D process. c-BN films were deposited on a high speed steel(SKH-51) substrate by hot filament CVD technique assisted with a microwave plasma to develop a high performance of resistance coating tool. c-BN films were obtained at a gas pressure of 20 Torr, vias voltage of 300 V and substrate temperature of $800^{\circ}C$ in $B_2H_6-NH_3-H_2$ gas system. It was found that a thin layer of hexagonal boron nitride(h-BN) phase exists at the interface between c-BN layer and substrate.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.221-222
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• 2006

This paper describes a Plasma Assisted Debinding and Sintering (PADS) equipment, which has been designed to process Metal Injection Molded (MIM) components. The use of a hybrid system combining a glow discharge with a conventional heating system makes debinding and sintering of MIM components, in the same heating cycle, a feasible industrial process. Characteristics as density, carbon content and mechanical properties are similar to traditionally processed MIM materials. The reduction of energy and gas consumption and shorter lead-times are economic advantages of PADS system. The clean environment of PADS is also an ecological advantage.

• Korean Journal of Materials Research
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• v.24 no.5
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• pp.266-270
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• 2014

Aluminum nitride(AlN) films were grown on the C-face and on the Si-face of (0001) silicon carbide(SiC) substrates using plasma-assisted molecular-beam epitaxy(PA-MBE). This study was focused on first-stage growth manipulation prior to the start of AlN growth. Al pre-exposure, N-plasma pre-exposure, and simultaneous exposure(Al and N-plasma) procedures were used in the investigation. In addition, substrate polarity and, first-stage growth manipulation strongly affected the growth and properties of the AlN films. Al pre-exposure on the C-face and on the Si-face of SiC substrates prior to initiation of the AlN growth resulted in the formation of hexagonal hillocks on the surface. However, crack formation was observed on the C-face of SiC substrates without Al pre-exposure. X-ray rocking-curve measurements revealed that the AlN epilayers grown on the Si-face of the SiC showed relatively lower tilt and twist mosaic than did the epilayers grown on the C-face of the SiC. The results from the investigations reported in this paper indicate that the growth conditions on the Si-face of the SiC without Al pre-exposure was highly preferred to obtain the overall high-quality AlN epilayers formed using PA-MBE.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.59.2-59.2
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• 2015

Modification of film structure and properties in inductively-coupled plasma (ICP) assisted dc and pulsed dc sputtering has been reported by Oya and Kusano [1] and by Sakamoto, Kusano, and Matsuda [2], showing drastic changes in films structure and properties by the ICP assistance in particular to the pulsed dc discharge. Although mechanisms involved in the modification has been reported to be the increase in energy transferred to the substrate, details of effects of low-energy ion bombardment on the modification and origin of an anomalous increase in the ion quantity by the ICP assistance to the pulsed dc discharge have not been discussed. In this presentation, mechanisms involved in film structure and property modification in ICP assisted dc and pulsed dc sputtering, in which a number of low-energy ions are formed, will be discussed based on ion energy distribution as well as effectiveness of energy transfer to the substrate by low energy particles [3]. The results discussed in this presentation will emphasize the fact that the energetic particles playing an important role in the film structure modification are those to be deposited, but not those of inert gas, when their energies range in less than 100 eV in the pressure range of magnetron sputtering.

• Journal of the Semiconductor & Display Technology
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• v.7 no.2
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• pp.63-67
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• 2008

The MgO protective layer plays an important role in plasma display panels (PDPs). Our previous work demonstrated that the properties of MgO thin film could be improved, which were deposited by ion beam assisted deposition (IBAD). However arc discharge always occurs during the IBAD process. To avoid this problem, oxygen neutral beam assisted deposition (NBAD) is used to deposit MgO thin films in this paper. The energy of the oxygen neutral beam was used as the parameter to control the deposition. The experimental results showed that the oxygen neutral beam energy was effective in determining in F/$F^+$ centers, crystal orientation, surface morphology of the MgO thin film, and the discharge characteristics of AC PDP. The lowest firing voltage $(V_f)$ and the highest secondary electron emission coefficient $(\gamma)$ were obtained when the neutral beam energy was 300 eV.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.7
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• pp.615-619
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• 2007

MgO layer plays an important role for plasma display panels (PDPs). In this experiment, ion beam assisted deposition (IBAD) methode was uesed to deposit a MgO thin film and the assisting oxygen ion beam energy was varied from 100 eV to 500 eV. In order to investigate the relationship between the secondary electron emission and the defect levels of the MgO layer, we measured the cathodoluminescence (CL) spectra of the MgO thin films, and we analyzed the CL peak intensity and peak transition. The results showed that the assisting ion beam energy played an important role in the peak intensity and the peak transition of the CL spectrum. The properties of MgO thin film were also analyzed using XRD and SEM, these results showed the assisting ion beam energy had direct effect on characteristics of MgO thin film.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.353.1-353.1
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• 2016

다공성 물질은 동공의 크기에 따라 미세동공(Micropore), 메조동공(Mesopore), 거대동공(Macropore)으로 나누어 분류한다. 다공성 재료의 장점은 높은 비표면적으로써, 촉매, 센서, 연료전지 전극, 에너지 저장장치 등으로의 이용 가능성을 보여주는 연구가 활발히 보고되고 있다. 종래의 연구는 두 가지 이상의 원소로 구성된 박막을 제작한 후 전기화학적 분해법, 선택적 용해법 등 습식공정을 통해 다공성 구조체를 제작하였다. 하지만 본 연구에서는 Au, Ag 타겟과 $CH_4$ gas를 이용해 ICP-assisted reactive magnetron sputtering 장비를 활용하여 450 nm 두께의 Au-C, Ag-C 박막을 제작하였다. 이후 연속적으로 RF 250 W를 ICP antenna 에 인가하여 $O_2$ plasma dealloying 공정을 통해 탄소(Carbon) 만을 선택적으로 제거함으로써, 건식 공정만으로 Si wafer ($10{\times}10mm^2$) 기판 위에 250 ~ 300 nm 두께의 다공성 Au, Ag 박막을 제작하였다. SEM (Scanning Electron Microscopy)를 활용하여 표면, 단면 형상을 관찰해 다공성 구조를 확인하였으며, AES (Auger Electron Spectroscopy)를 통해 plasma dealloying 전 후 박막의 조성변화를 관찰하였다. 따라서 plasma dealloying 공정으로 제작된 다공성 Au, Ag 박막은 기존의 습식 공정 대비 청결하고 신속한 공정이 가능하며 높은 재현성을 통해 위의 적용분야에 보다 쉽게 사용될 수 있을 것으로 기대된다.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.203-203
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• 2010

Nano-crystalline Si thin films were deposited on polymer and glass by inductively coupled plasma (ICP) - assisted RF magnetron sputtering at low temperature in an argon and hydrogen atmosphere. Internal ICP coil was installed to increase hydrogen atoms dissociated by the induced magnetic field near the inlet of the working gases. The microstructure of deposited films was investigated with XRD, Raman spectroscopy and TEM. The crystalline volume fraction of the deposited films on polymer was about 70% at magnetron RF power of 600W and ICP RF power of 500W. Crystalline volume fraction was decreased slightly with increasing magnetron RF power due to thermal damage by ion bombardment. The diffraction peak consists of two peaks at $28.18^{\circ}$ and $47.10^{\circ}\;2{\theta}$ at magnetron RF power of 600W and ICP RF power of 500W, which correspond to the (111), (220) planes of crystalline Si, respectively. As magnetron power increase, (220) peak disappeared and a dominant diffraction plane was (111). In case of deposited films on glass, the diffraction peak consists of three peaks, which correspond to the (111), (220) and (311). As the substrate temperature increase, dominant diffraction plane was (220) and the thickness of incubation (amorphous) layer was decreased.

• Progress in Superconductivity and Cryogenics
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• v.14 no.1
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• pp.1-3
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• 2012

LMO($LaMnO_3$) buffer layer of superconducting coated conductor was deposited on IBAD-MgO template in the plasma atmosphere at $650^{\circ}C$ which is relatively low compared with conventional deposition temperature of more than $800^{\circ}C$. Deposition method of LMO was DC sputtering, and target and deposition chamber were connected to the cathode and anode respectively. When DC voltage was applied between target and chamber, plasma was formed on the surface of target. The tape substrate was located with the distance of 10 cm between target and tape substrate. When anode bias was connected to the tape substrate, electrons were attracted from plasma in target surface to the tape substrate, and only tape substrate was heated by electron bombardment without heating any other zone. The effect of electron bombardment on the surface of substrate was investigated by increasing bias voltage to the substrate. We found out that the sample of electron bombardment had the effect of surface heating and had good texturing at low controlling temperature.

• Proceedings of the Korean Vacuum Society Conference
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• 1996.06a
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• pp.40-41
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• 1996

Nitridation technique has been receiving much attention for the formation of a thin nitrided buffer layer on which high quality nitride films can be formedl. Particularly, gallium nitride (GaN) has been considered as a promising material for blue-and ultraviolet-emitting devices. It can also be used for in situ formed and stable passivation layers for selective growth of $GaAs_2$. In this work, formation of a thin nitrided layer is investigated. Nitrogen electron cyclotron resonance(ECR)-plasma is employed for the formation of thin nitrided layer. The plasma source used in this work is a compact ECR plasma gun3 which is specifically designed to enhance control, and to provide in-situ monitoring of plasma parameters during plasma-assisted processing. Microwave power of 100-200 W was used to excite the plasma which was emitted from an orifice of 25 rnm in diameter. The substrate were positioned 15 em away from the orifice of plasma source. Prior to nitridation is performed, the surface of n-type (001)GaAs was exposed to hydrogen plasma for 20 min at $300{\;}^{\circ}C$ in order to eliminate a native oxide formed on GaAs surface. Change from ring to streak in RHEED pattern can be obtained through the irradiation of hydrogen plasma, indicating a clean surface. Nitridation was carried out for 5-40 min at $RT-600{\;}^{\circ}C$ in a ECR plasma-assisted molecular beam epitaxy system. Typical chamber pressure was $7.5{\times}lO^{-4}$ Torr during the nitridations at $N_2$ flow rate of 10 seem.(omitted)mitted)